Issues securing Webmail with SSL Certificate

My webmail client (squirrelMail) is working perfect, but I would like to run it over https. The url for the web mail client is webmail.domain.com. I had a SSL certificate built by a Certificate Authority (godaddy) for this URL. In ISPConfig, I enabled SSL for this site. I also copied the certificate into the SSL Certificate box and saved the certificate. I opened port 443 on my firewall. But when I go the website httpS://webmail.domain.com, the browser hits me with a pop saying, "webmail.domain.com has sent an incorrect or unexpected message."

I did a little research and I found I have to copy the certificate, intermediate certificate and key file onto the server and edit the ssl.conf file to point the SSLCertificateFile, SSLCertificateKeyFile and SSLCertificateChainFile variables to the correct path. I looked in the /root/ispconfig/httpd/conf directory and didn't find a ssl.conf file. I did a search for ssl.conf and found two (/etc/apache2/mods-available/ssl.conf, /etc/apache2/mods-enabled/ssl.conf). In both of these files there is no sections for any of these variables. Should I create a ssl.conf and put in the /root/ispconfig/httpd/conf or edit one or both of the existing ssl.conf? Or is there a way this can be handled through the ISPConfig control panel? Thanks in advance for any help.

I took a look at my vhosts_ispconfig.conf file and noticed I don't have a NameVirtualHost XXX.XXX.XXX.XXX:443 or VirtualHost XXX.XXX.XXX.XXX:443 even though I have the SSL box checked in the ISP Site Control Panel. I have restarted the web-server service since I checked this box. I tried to edit this file and add the appropriate information, but when I restart the service the changes are erased.

Thanks for the reply. I copied the gd_intermediate_bundle.crt file into the /var/www/webXX/ssl directory. I then copied the other cert into the SSL Certificate textbox and selected the save certificate. I then add "SLCertificateChainFile /var/www/webXX/ssl/gd_intermediate_bundle.crt" line to the Apache Directives
(Optional): I saved these settings and restarted the web-server and I still get the same error when I go to the https site.

That's all that is in my Vhosts_ispconfig.conf file there is nothing in there for 443. This is with adding the SLCertificateChainFile /var/www/webXX/ssl/gd_intermediate_bundle.crt" line to the Apache Directives
(Optional) textbox in the ISPConfig control panel. Also shouldn't there be commands "SSLEngine on
SSLCertificateFile /var/www/webXX/ssl/www.yourdomain.com.crt
SSLCertificateKeyFile /var/www/webXX/ssl/www.yourdomain.com.key" in there as well? Thanks again for all the help.

just a thought,
did you create the ssl csr or self signed crt for the site using the ispconfig control panel before you had godaddy sign the csr?
if not you might need to create the ssl crt using the control panel so that it adds the proper lines to the Vhosts_ispconfig.conf then replace the crt and key with in the ssl dir with what godaddy built for you.

Thanks, that work like a charm! I create a self signed cert and it did add the virtual host :443 and the appropriate lines. I then placed the godaddy signed cert in the SSL Certificate textbox and selected save certificate.